Automatic coal-feed-distributing device



April 9, 1929. F. GRAVES ET AL 3 5 AUTOMATIC COAL FEED DISTRIBUTING mavzcn I Filed April 30, 1925 3 Sheets-Sheet 1 F Va IVs/K172 J! Mari/'11 Ap 1929. F. GRAVES ETAL 1,708,879

AUTOMATIC COAL FEED DISTRIBUTING DEVICE Filed April 30, 1925 3 Sheets-Sheet 2 April 9, 1929. F. GRAVES ET AL AUTOMATIC COAL FEED DISTRIBUTING DEVICE Filed April 50, 1925 5 Shets-Shegt j'vdnn Lilla/i137 Patented Apr. 9, 1929.

UNITED STATES 'PATEN T OF F ICE.

FRANK GRAVES, OF ST. PAUL, AND MELVIN S. MARTIN, OF MINNEAPOLIS, MINNE- SOTA; SAID GRAVES ASSIGNOR TO SAID MARTIN.

AUTOMATIC COAL-FEED-DISTRIBUTING- DEVICE.

Application filed April 30, 1925.

Our invention has for its object to provide automatic means for operating distributing spouts and especially the fuel feed-distributing spouts for automatic stokers, and to this end it consists of the novel devices and con'lbinatiens of devices hereinafter described and defined in the claims.

As is well known, in the commonly used forms of automatic stokers for boiler in,- stallations and the like, coal is delivered to such stokers from hoppers and which coal is delivered to the hoppers and destributed therein by one or more swinging spouts which are constantly. kept filled with coal from a suitable source of supply. It is now customary to swing these spouts from time to time by hand to distribute the coal in the hoppers. This is very laborious work and each spout must be moved every few minutes which necessitates the constant attention of one or more attendants depending on the size of the boiler installation and the numberof coal distributingspouts to be operated. This method of intermittently moving coal distributing spouts is objectionable, aside from the cost of operation, for the reason that the coal is not evenly distributed in the hoppers; and furthermore when the distrib uting spouts are standing idle, the weight of the colums of coal therein packs the underlying coal in the hoppers so that the coal in the hoppers is unevenly packed and when delivered to the stokers varies materially in weight throughout the length of the hop pers and hence produces an uneven feed to said stokers.

By the use of our invention, the fuel-distributing spouts are automatically kept in motion at a given speed so that the fuel is evenly distributed. in the hoppers and under the same pressure throughout the entire lengths thereof, and without manual. labor.

In the accompanying drawings, which illustrate the invention, like characters indicate like parts throughout the several views. V

Referring to thedrawings:

Fig. 1 is a fragmentary front elevation 7 showin the invention aualied to a boiler installation and an automatic stoker to which fuel is supplied by a hopper and distributing spouts; h

Fig. 2 is a fragmentary elevation of the cylinder and piston motor and parts associated therewith removed from the boiler Serial No. 26,877.

installation, some parts being sectioned;

Fig. 31s an elevation of the oil pump and parts associated therewith, with some parts roken away and sectioned and with the drive shaft of the pump sectioned on the linev 3- of Fig. 1, on anenlarged scale;

Fig. 4 is a fragmentary detail view, on an enlarged scale, of the right-hand end portion of the cylinder and piston motor, and controlling valve and trip therefor;

Fig. 5 is a right-hand elevation of the parts-shown in Fig. 4; and

Fig. 6 is a detail view principally in sectron, taken on the line 6-6 of Fig. 5.

For the purpose of showing the invention applied in working position, there is shown in the drawings a boiler installation, indicated as an entirety by the numeral 7., and an automatic stoker indicated as an entirety by the numeral 8, with the exception of its drive shaft 9. Fuel is delivered to the automat-ic stoker 8 from a hopper 10 and said hopper is kept supplied with fuel by, as shown, three distributing down spouts 11 leading from a suitable source of supply, not shown.

These distributing down spouts 11 are pivotally suspended from their upper ends, as indicated at 12, for oscillatory movement over the hopper 10, or in other words, parallel to the front face of the boiler installation 7. Said distributing spouts 11 are laterally spaced so that when properly oscillated, they will distribute fuel in the hopper 10, in which their lower ends project throughout its entire length. The distributing spouts 11 are held against movement transversely of the hopper 10 but with freedom for oscillatory movement longitudinally thereof by a track rail 13 secured to and extending above 9 the hopper 10 and co-operating guide rollers,

not shown, on the inner faces of said spouts.

The parts thus far described are of standard and well known construction.

Referring now in detail to the invention, the numeral 14 indicates a cylinder, and the numeral 15 a co-operating piston, which cylinder and piston constitute a reciprocating engine or motor. The piston 15 is secured to the intermediate piston rod 16, the end portions of which work through stuffing boxes 17 in the heads 18 of the cylinders 14. The cylinder heads 18 are clamped onto the ends of the cylinders 14 by a plurality of circumferentially spaced portlon of a long suitable make and, as

-journaled a grooved wheel 21. The inner endsof the bearings afford abutments 22 for a purpose that will presently appear, and which abutments are laterally offset in respect to the piston rod 16.

The cylinder 1 L is'sc cured by a pair of hanger brackets to a horizontal plate 24; on the front of the boiler installation 7. The three distributing spouts 11 are connected near their lowerends of common oscillatory movement by a chain 25. These distributing spouts 11 are oscillated from the piston 15 by a pair of cables 26 having one of their ends longitudinally spaced outward of the "ends of the cylinder 14 and anchored at 27 to the plate 2%, and their other ends are at tached one to each of the outer distributing spouts 11; These cables 26 are arranged to run over the grooved wheels 21 on the piston rod 16 a'nd relatively large grooved wheels 28. loosely journaled on hanger brackets 29 secured one to each 01" the ends of the plate 24. A turn buckle 30 is interposed in each cable 26 totake up the slack therein. The arrangement of the cables 26 is such that the distributing spouts 11" are given twice the oscillatory movement of that of the travel of the piston 15. a V

The piston 15 isoperated by a fluid X, preferably oil, zppliedu'nder pressure to the cylinder 14 by. an oil pump of the rotary type and indicated as'anv entirety by the numeral 31wvith the exception of its drive shaft The oil pump 31 may beof any shown, is driven from the stoker drive share 9 by a flexible cou pling 33'. I

For changing the direction of flow of oil X'into the cylinder 14:, from one side of the piston'15 to the other to operate the same,

there is provided an oscillatory valve media a valve casing'EH secured to the right-hand cylinder head 18. Formed in the'valve casing 'is'an'intake port 35 con-' 7 nect'ed to the high pressure side of the pump 31 by an oil pipe 36. Also formed in the valve casing 3i are discharge ports 37 and 38 and a' return port 39. p The dischargeport 37'leads to the right-hand end of the cylinder 1.4: through a port 40 in the respective cylinder head 18 and the dischargeport 38 connected to the left-hand end of the cylinder 14 by an O1l pipe 41. The return port 39 is connected toithe' low pressure side of the pump 31 by an oil pipe 4-2. As the valve is set, in -Fig. 6, the flow of oil from the high pressure side of the pump31 isthrough thepipe 36, ports 35 and 38 and pipe 11 to theleitrhand'end of the cylinder to move the piston '15 in the direction of rearrow marked thereon in Fig. 2.

interposed in the oil return pipe 42, is a surplus oil tank or reservoir 43, and interposed in the pipe 36 is a hand-controlled cut-off valve 4-4:. The pipe 36 between the pump 31 and valve 4A connected to the return pipe 42 by a by-pass 15 having inten posed therein a pop or relief valve 46 in the form of a ball normally held on its seat by a spring 47 and which spring is held under tension by a screw plug 48 in the casing of the valve l6. This valve 46 is arranged to permit a circulation of oil from the high pressure side of the pump 31 to the low pressure side thereof. In some instances, it might be desirable to form this by- )ass directly in the pump 31. Attached to the outer end of the stem 49 of the valve 33 is an upstanding crank arm 50 having on its free end a laterally projecting stud or pin 51.

To automatically reverse the valve 33 at the limit of each stroke of the piston 15, and thereby cause the oil X to flow from the high pressure side of the pump 31 first in one end oi the cylinder 1.4 and then in the other to reciprocate the piston 15 and oscillate the distributing spout 11, there is provided a trip arranged to be actuated by the abutments 22 at the ends of the piston rod 16. This trip includes a push bar 52 that is square in cross section, extends parallel to the piston rod 16 and is mounted for endwise sliding movement in seats 53 formed in extensions on the cylinder heads 18. Secured to the ends of the push bar 52, outward of the cylinder heads 18, is a pair of upstanding arms 54 arranged to be alternate y engaged by the respective abutments 22 durin their travelling movcmcnts toward the cyFinder 14. Secured to the push bar 52 between the righthand cylinder head 18 and arm 5i is an outwardly projecting lug in the form of a fiat plate arranged to alternately engage a pair of diverging striking flanges 56 on :1 depending crank 57 loosel mounted on a stud 58 secured to the ri ht-hand cylinder head 18. These striking llangcs 56 are also arranged to alternately engage the pin 51 on the crank 50 and thereby reverse the valve 33.:

Formed with the crank 57 is a pair of diametrically opposite stop lugs 59 arranged to alternately engage a stop pin 66 on the valve casing 3st and limit the movements of the crank 57. A coiled spring 61 attached to a pin 62 on the free end of the crank 57. and anchored to the projecting end of one of the tie rods 19, normally holds the crank 57 with either one of its stop lugs 59 against the stop pin 60.

The initial movementof the crank 57 is imparted by the push rod 52, as the same is moved by the piston rod 16, when its lug 55. engages one of the striking flanges 56 on said crank. At the time the push rod 52 moves the crank 57 beyond a dead center. the spring 61 completes the movement of mos-eve said crank. During this movement of the crank 57 by the spring 61,the opposite striking flange 56 from the one just engaged by the ing 55 engages the pin 51 on the crank 50, moves the same in the direction of the movement of the push bar 52, and reverses the valve 33 with a quick action. At the completion of each movement of the crank 5'5, the same is yieldingly held by the spring 61 with one of its stop lugs 59 in engagement with the stop pin 60. It is important to note that the spacing of the striking flanges 56 is such that the crank 57 has a movement entirely independent of the push bar 52 at the time said crank is operated by the spring 61. The oil X is supplied to the cylinder 14 through a filling opening 63 normally closed by a screw plug 64.

Operation.

WVhen the automatic stoker 8 is in operation, the oil pump 31 is constantly driven by the stoker drive shaft 9, and the oil from the high pressure side of said. pump is forced through the pipe 36, ports and 38, pipe 41 and into the left-hand end of the cylinder 14 and moves the piston 15 in the direction of the arrow marked on Fig. 2. It will be noted that the piston 15 is just about completing its stroke to the right, and the left-hand arm 54 on the push bar 52 is engaged by the respective abutment 22 and has moved said push bar 52 sufficiently to cause its lug 55 to engage the right-hand striking flange 56 and move the crank 57 into an intermediate position, and only a slight further movement of said push bar is required to move said crank beyond a dead center so that the spring 61will complete the movement of said crank and reverse the valve 33 in the manner previously described.

It may be here stated, that the oil X in front of the piston 15 is being discharged from the right-hand end of the cylinder 14 through the ports 40, 37 and 39 and returned to the pump 31 on the low pressure side thereof through the pipe 42. The purpose of the reservoir 43 isto always alford a supply of oil to the pump in case the cylinder 14 is not completely filled. When the valve 33 is in a reverse position from that shown in Fig. 6, the oil from the high pressure side of the pump 31 will flow through the pipe 36, ports 35, 37 and and into the iight-hriiid end of the cylinder 14 and reverse the movement of the piston 15 and thereby cause the same to travel toward the left. The oil discharged from the cylinder 14 in advance of this movement of the piston 14 will flow through the pipe 41, ports 38 and 39 and return to the low pressure side of the pump through the pipe 42. It will thus be seen that the automatic trip will intermittently reverse the valve 33 and which, in turn, imparts a like movement to the distributing spouts 11 and thereby causes the same to evenly distribute fuel in the hopper 10 throughout the entire length thereof. 1 1

By manipulating the valve 44, the speed of the motor or, in other words, the piston 15, may be varied at will or, if desired, can be stopped by closing said valve, and at which time either part or all of the oil will move through the by-pass from the high pressure side of the pump 31 to the low pressure side thereof.

The above described invention has, in actual usage, proven highly efficient for the purpose had in view.

What we claim is:

1. The combination with a stoking apparatus and a feed hopper therefor, of an upright distributing spout mounted for oscillatory movement longitudinally of the hop per with its lower end. substantially in the plane of a fuel level to be maintained in the hopper, a cylinder and piston motor, operating connections including a cable from said piston to said spout, a circulating fluid for operating the piston, and means for controlling the circulation of said fluid to intermittently reverse the motor to oscillate the cable.

2. The combination with a stoking apparatus and a feed hopper therefor, of an upright distributing spout mounted for oscillatory movement longitudinally of the hopper with its lower end substantially in the plane of a fuel level to be maintained in the hopper, a cylinder and piston motor, operating connections including a cable from said piston to said spout, a circulating fluid for operating the piston, and means including a valve for controlling the circulation ofsaid fluid to reverse the piston to oscillate the cable.

3. The structure defined in claim 2 in further combination with a relief-valveequipped by-pass for controlling the circulation of said fluid to the cylinder.

4. The structure defined in claim 2 in further combination with a relief valve equippedby-pass for controlling the circulation of said fluid to said cylinder, and a cutoff valve between the by-pass and cylinder for stopping or regulating the circulation of said fluid to the cylinder.

5. The combination with a stoking apparatus and a feed hopper therefor, of an upright distributing spout mounted for oscillatory movement longitudinally of the hopper with its lower end substantially in the plane of a fuellevel to be maintained in the hopper, a cylinder and piston motor, the piston of said motor having a piston rod working through opposite ends of the cylinder, a pair of reversely extended cables reversing the motor to impart oscillatory having one of their ends connected to the movement to the spout.

' spout and their'other ends attached to the In testimony whereof we aflix our signaends 0f said piston rod, a pair of guides for tures.

5 the cables, a circulating fluid for operating the piston, and means for controlling the FRANK GRAVES. circulation of said fluid for intermittently MELVIN S. MARTIN. 

